The coalition to pass California’s affordable housing initiative, Proposition 10, has a message for voters ahead of the November 6 midterm elections: “You are the company you keep.”

Yes on 10 released an ad on Sept. 30 that exposes the close ties between Donald Trump and the wealthy real estate tycoons who have financed efforts to defeat the bill. Prop 10 would repeal the Costa-Hawkins Rental Housing Act, thereby allowing state and local governments to pass rent control ordinances, thus hurting the profits of large property developers.

The campaign for Prop 10—which is sponsored by AIDS Healthcare Foundation and supported by the ACLU and the California Democratic Party, among others—called out four multi-millionaire and billionaire “predatory landlords:” Geoffrey Palmer, Michael Hayde, Jackie Safier, and Stephen Schwarzman. Records show each has contributed financially to Trump’s presidential election, reelection, and/or inaugural campaigns.

In August 2016, Politico reported Palmer had emerged as the single largest Trump donor in the United States following his $2 million contribution to the Rebuilding America Now PAC. Also during the 2016 election cycle, Safier and Hayde gave, respectively, $233,900 and $12,500 to the Republican National Committee and Trump’s campaign. And for his part, after Schwarzman pledged $250,000 for the President’s inaugural committee, The Washington Post reports that by 2018 he became one of the President’s most generous donors. The paper also noted the billionaire’s role as a “key advisor with rare and regular access” to the White House.

Together, all four have contributed more than $10 million to defeat Prop 10, bringing the total amount of money raised by opposition PACs to more than $45 million—which exceeds by more than three times the total contributions to pro-Prop 10 groups.

Despite the use of Trump as a political wedge in hopes of uniting Democratic support for Prop 10, and despite the endorsement from California’s Democratic Party, divisions over the measure are not measured across strictly partisan lines. Progressive favorite Lieutenant Governor and gubernatorial candidate Gavin Newsom, for example, is an outspoken member of the “No” camp. At a housing conference in March, he said he was open to restrictions but thinks outright repeal would “have unintended consequences on housing production that could be profoundly problematic,” potentially worsening a housing crisis fueled by the dearth of supply and excess of demand.

Los Angeles Mayor Eric Garcetti, on the other hand, supports Prop 10. “I’ve always believed that those who live closest to a given block or a street know what’s best. Local government should have control over their own city,” he said, City News Service reported.

AHF believes this is a larger fight. “From a social justice point of view,” says AHF President Michael Weinstein,“we are seeing mass displacement… and we feel like shelter is the most basic right and people are being deprived of that and we don’t believe that the marketplace can handle providing shelter to everyone who needs it.”

From a public health point of view, he adds, “we see our clients being rendered homeless or being pushed further and further out from where our healthcare centers are.”

Yes on 10 also noted that Big Pharma contributed $500,000 to an anti-Prop 10 PAC, ostensibly with the sole intention of defeating AHF’s Weinstein who has long challenged drug pricing and practices of pharmaceutical companies.